Generally, fabrication processes of semiconductor devices may involve an ion implantation process. During the ion implantation process, p-type impurities, such as boron (B) and indium (In), or n-type impurities, such as phosphorus (P) and arsenic (As), may be ionized and implanted into a silicon wafer. Such an ion implantation process may be used because it may be less difficult to control the concentration of impurities implanted into a silicon wafer.
An ion implanter for implementing the ion implantation process may include an arc chamber from which ion sources (i.e., positive ions) may be emitted. In the arc chamber, electrons emitted from a filament may be forcibly collided with a neutralized reactant gas so that thermoelectrons are separated from the reactant gas, thereby producing and emitting positive ions.
However, in a conventional ion implanter, a number of thermoelectrons emitted from a filament in an arc chamber may be lost through a body of the arc chamber before colliding with a reactant gas. Due, at least in part, to the loss of the thermoelectrons, the current density of positive ions emitted from the arc chamber may be reduced.